body {
  width: 100%;
  background-image: url(../images/screen.jpg);
  background-position: left top;
  background-size: 100% auto;
  background-repeat: no-repeat;
}
#screen {
  width: 837px;
  height: 462px;
  margin: 20px auto;
  background-color: #FFFFFF;
  overflow-y: scroll;
}
